With respect to the collection of human wastes in holding tanks of vehicles, earlier in conjunction with trains:
In 1914, Harrison Cronk in his U.S. Pat. No. 1,085,850, disclosing a railroad closet tank, installed a nozzle high at one end of the tank to admit steam, when flusing out the contents of the tank down through a drain located near the center of the closet tank;
In 1914, William West in his U.S. Pat. No. 1,112,507, disclosing a water closet for railway carriages, provided a flushing water circular pipe opening at a low location at a holding tank end, opposite to the other end which in turn was nearby a discharge opening in a downwardly sloping tank bottom; and
In 1915, Anna Clarke in her U.S. Pat. No. 1,155,550, disclosing a sewage system for railway cars, arranged for a flushing water circular pipe opening at a high location at a holding tank end opposite to the other end having a low location discharge circular pipe opening.
Subsequently through the years other types of holding tanks were installed in other vehicles, such as those disclosed in U.S. Pat. Nos. 2,817,091 of 1957 regarding a mobile sanitary trailer; 3,501,778 of 1970, disclosing a high centrally located spray tube in a tank of a self contained sewerage system; 3,556,417 of 1971 illustrating a combination toilet and holding tank; 3,597,768 of 1971 describing a holding tank for a mobile vehicle; 3,760,430 of 1973 disclosing an adapter apparatus for a portable sewage disposal system; 3,897,599 of 1975 illustrating and describing a holding tank, which upon being emptied, employs a self contained internal flailing tube discharging rinsing water under high pressure at changing and multiple locations to clean out the interior of the holding tank; and 4,028, 746 of 1977 disclosing a portable toilet utilizing a high entry opening for flushing water used periodically to clean out the holding tank.
Then it is believed, subsequent to the filing of the original application, of which this application is a continuation in part application, a flushing unit is now offered on the market under the trademark "No-Fuss Flush", which sprays water in multiple directions from spaced holes formed in the exterior of a hollow cylinder which is positioned inside a vehicle holding tank.
All these representative disclosures of patents indicate the extensive development of holding tanks over a number of years. Yet today vehicles, such as travel trailers and motor homes, which have holding tanks are still not equipped with adequate flushing attachments to be used, when the entire holding tank must periodically be drained and completely cleaned out. Mr. Richard F. Artzer in his U.S. Pat. No. 3,897,599 did indicate the need for more extensive cleaning by employing his flailing tube. Also the "No-Fuss Flush" flushing unit indicates this need. However, it is still believed there remains a need for insuring a holding tank that can be sufficiently cleaned out, without following a practice, still commonly undertaken, of extending a garden type hose through the living spaces of a trailer or motor home to the bathroom and then using water supplied via the hose to completely rinse out the holding tank. There remained a need to be able to secure a garden hose directly to a holding tank attachment lcoated outside the interior of a motor home or travel trailer, and when the cleaning water was turned on for a short while, as the tank drain was opened, that thereafter the interior of the holding tank would be sufficiently cleaned out to remove the debris and all sources of odor.